Coxsackievirus B3 (CVB3) is a leading cause of chronic heart inflammation and heart failure in children and young adults. Persistent CVB3 infection is not associated with the mature virus but instead with latent expression of its RNA genome in cardiomyocytes. Our preliminary observations suggest that the presence of CVB3 RNA disrupts how cardiomyocytes normally respond to inflammatory stimuli, which may be important for establishing a chronically inflamed state. The objective of this proposal is to defin the molecular rewiring that takes place in cardiomyocytes upon chronic infection with CVB3. Our hypothesis is that persistent expression of CVB3 RNA disrupts the posttranscriptional signaling response of cardiomyocytes to proinflammatory stimuli. During the R21 phase, we will develop high-throughput biochemical methods to measure signaling and transcript stability at the systems level. In the R33 phase, these assays will be combined to examine posttranscriptional signal processing in cultured cardiomyocytes expressing CVB3 RNA and stimulated with proinflammatory cytokines. The data will ultimately serve as the basis for a computational-systems model that connects signaling events to gene expression and transcript stability. Aim #1 of the R21 phase is to develop quantitative, systems-level bioassays to measure kinase-phosphatase activation in cardiomyocytes chronically infected with CVB3. Aim #2 of the R21 phase is to develop a real-time, multiplex RNA stability assay for profiling half-lif regulation of NF-?B transcripts in cardiomyocytes. Aim #3 of the R33 phase is to interrogate intracellular dynamics triggered by proinflammatory cytokines and build a predictive, data-driven systems model that captures CVB3-induced cardiomyocyte rewiring. The long-term goal is to use the model to propose novel interventions that can correct posttranscriptional signal processing in patients with persistent CVB3 infection.